Concrete blocks have been commonly used in construction for many decades. However, since the 1980's several companies have looked for systems, which could be assembled more rapidly. A dry stack system was introduced in order to reduce skilled labour requirements, permit faster stacking and eliminate wet material. Initially dry stack systems suffered from quality control. Variations in height dimensions of 1/16 inch caused deviations from plumb after just three or four courses and required shims to adjust the height. However, while still suffering from some height variation, dry stack systems have since improved and are now competitive in many more market segments than before.
Machines to manufacture concrete blocks provide for a hopper to temporarily hold the mixed concrete until it can be poured into a mold. Many different cast moldings are known but generally the negative shape of the finished block is formed on the inside of the mold. The mold is placed on a support board and then pushed onto a vibrating table where it is filled with concrete from the hopper. As soon as the mold is filled with concrete, a pressure plate descends upon the concrete in the mold. Either concurrently with vibrating the vibrating table or after, pressure is applied to the fresh concrete in the mold by depressing the pressure plate. The pressure plate is raised vertically and then the support plate is raised with the finished pre-cast brick remaining on the support board. The support board and brick are carried away by a board carriage for onward transportation by a conveyor system. A new support board is then pushed into the mold, which rests on the vibrator plate. Generally, such manufacturing systems include a turntable with several work stations as well as the concrete block molding machine. Such systems are large, relatively expensive and difficult to move.
Accordingly, it is an object of the invention to provide a compact mold-making machine that is easily moved and which produces concrete blocks of precise accuracy.